Right firstly it's a 2007 2.0 TDi Sport BKD engine. For the last 2 days when it's started from cold its making more than usual noise. Sounds like a clattering but can't tell where its coming from. It's always gone within 5 mins of driving. Engine does sound louder than usual and not as smooth bit could be hearing things as so worried. Suspect DMF but getting increasingly concerned it could be the start of oil pump failure. Any ideas for diagnosis would be much appreciated and may stop me having a coronary!!!